FIG. 1 is a view illustrating a conventional single-crystal ingot manufacturing apparatus.
The single-crystal ingot manufacturing apparatus illustrated in FIG. 1 includes a crucible 10, a seed crystal 30, heat-shields 42 and 44, a heater 50, a wire 62, and a pulling motor 64.
With a silicon single-crystal manufacturing method using a Czochralski process, after the crucible 10 is filled with polysilicon, the crucible 10 is heated by the heater 50 to melt the polysilicon, which results in silicon melt 20. Next, the seed crystal 30 is lowered to come into contact with the silicon melt 20, and thereafter is pulled upward by rotating the wire 62 connected to the seed crystal 30 using the pulling motor 64 so as to subsequently form a neck portion, a shoulder portion, and a diameter portion (or a straight body) having a predetermined diameter of an ingot. In this way, growth of the single-crystal ingot is completed. In this case, the heat-shields 42 and 44 serve to shield radiant heat generated from the silicon melt 20, the crucible 10, and the heater 50.
Slip dislocation occurs in a lower end of the seed crystal 30 at a high density from thermal shock due to a rapid temperature difference when the seed crystal 30 comes into contact with the silicon melt 20. A necking operation of removing the slip dislocation is essential, in order to grow a dislocation-free silicon single-crystal ingot. The necking operation developed by Dash creates an elongated neck portion having a diameter within a range of about 3 mm to 4 mm and a length within a range of about 100 mm or more.
The neck portion having a small diameter within a range of 3 mm to 4 mm may be damaged with increasing diameter and weight of the silicon single-crystal ingot during growth, which causes serious accidents, such as fall of the single-crystal ingot, etc. In particular, a greater diameter and weight of the single-crystal ingot may worsen damage to the neck portion.